1. Field of the Invention
This invention relates to a frame for supporting a scanner head.
Scanners are utilized in a number of industries where it is desired that a surface be traversed in order to measure its characteristics, to lay down a layer of material such as an image and similar applications. One specific application is for the ultrasonic scanning of the floors and walls of metal tanks to determine thickness and erosion/corrosion damage of relatively large areas. In order to scan such areas one traditional approach is to grid the area and then make a scan manually.
2. Description of the Prior Art
The present invention provides a portable frame for a scanner head that may be readily disassembled into several components that are easily transported to a job site. The disassembled components are relatively light for easy carrying but also are of relatively small cross-section so that they can be passed through small openings such as manholes.
3. Summary of the Invention
Once on the job site, the parts may be readily assembled and mounted on the surface to be scanned. The mechanism is designed to be simple and permits a single scanner and transducer to scan accurately at high speed and avoid problems associated with large multi-transducer systems and also be very cost effective as compared to manual scanning.
In a preferred embodiment, the frame has six main components which are four sides, a traversing rail that is driven along two opposite sides and a scanner head carried by the traversing rail for reciprocating along the rail. The four corner joints of the four sides are readily disassembled by a thumbscrew and the traversing rail is easily disassembled from the two sides. The scanner head is easily separated from the rail by removal of a pin.
In a preferred embodiment, the four sides join together to make a frame approximately four feet square which carry a traversing rail that is approximately eight feet long to give a scan area of approximately eight feet by four feet. A direct current servo motor drives the rail through a chain to traverse the four feet back and forth over the frame. A second identical direct current servo motor drives the scanner head through a chain from one end of the rail to the other over the eight foot length.
Any suitable control system and scanner senser may be used and are not part of this invention. A typical system could use an ultrasonic scanner of the type used in the Alara II controlled scanning system available from Virginia Corporation of Richmond; 3605 Mayland Court; Richmond, Va. 23233. Scanners could also be based on eddy currents, jet printers for images, and other devices that scan a surface to measure physical characteristics or deposit material to form an image. A scan can be at a rate of between 6.5 and 8 square feet per minute or lesser or greater depending on the needs of a particular system.